[RFT PATCH] ARM64: dts: meson-gxbb: Add reserved memory zone and usable memory range
From: afaerber@suse.de (Andreas Färber)
Date: 2017-01-15 15:44:26
Also in:
linux-amlogic, linux-devicetree, lkml
Am 23.12.2016 um 10:42 schrieb Heinrich Schuchardt:
quoted hunk ↗ jump to hunk
it really makes a difference if we write memory at 0 { device_type = "memory"; linux,usable-memory = <0x0 0x1000000 0x0 0x7f000000>; }; or memory at 0 { device_type = "memory"; reg = <0x0 0x1000000 0x0 0x7f000000>; }; The second version leads to failure of the Odroid C2. When I looked at /sys/firmware/fdt I saw this difference:--- fails +++ works memory at 0 { - device_type = "memory"; reg = <0x0 0x0 0x0 0x78000000>; + device_type = "memory"; + linux,usable-memory = <0x0 0x1000000 0x0 0x7f000000>; };I found the following sentence in the NXP forum: In case you want to overwrite the memory usage passed from u-boot, you can use "linux,usable-memory". https://community.nxp.com/thread/382284
The Odroid-C2 is in mainline U-Boot. Please submit a patch to U-Boot instead of forcing the creation of unnecessary new .dts files onto everyone due to hardcoded linux,usable-memory properties. In fact, it already reserves 0x1000000, so it seems you are merely using an older U-Boot. http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/mach-meson/board.c;h=f159cbf849f75ab046e6f3a025bbc97c0bcfd59d;hb=HEAD#l39 I would bet that the upper limit is unrelated here. Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 N?rnberg, Germany GF: Felix Imend?rffer, Jane Smithard, Graham Norton HRB 21284 (AG N?rnberg)